The present invention relates to a multi-stage forming machine with a final forming station for dividing combined parts into in each case at least two product parts.
Multi-stage forming machines, which divide combined parts into two product parts in a final forming station are used, for example, for producing ball bearing races. In the case of most known forming machines, the product parts produced, for example an inner race and an outer race, fall under their own weight onto a chute arranged beneath the forming station and slide on the said chute out of the forming region of the forming machine.
These forming machines have a whole series of disadvantages. For instance, the machine speed is restricted by the falling of the product parts, dependent on acceleration due to gravity. The product parts themselves may possibly suffer surface damage due to striking the chute, which leads to inaccuracies and makes reworking necessary. Therefore, it is not possible for the forming machine to produce accurately finished product parts.
A further disadvantage is that the product parts are discharged in a disorderly manner. There is no clear production sequence of the discharged product parts, with the result that quality control and possible readjustment of the forming machine and the rejection of defective product parts are made more difficult. This has the effect that, in particular in the case of safety parts, too many possibly defective product parts have to be rejected. In addition, it is necessary in a subsequent separate operation for the two types of product part produced to be sorted and possibly for the product parts to be aligned suitably for the operations which follow.
In the case of multi-stage forming machines for producing a single product part per working cycle, it has been possible to eliminate some of the corresponding disadvantages by arranging transfer tongs at the final forming station for transferring the product part into the discharge chute. Such a forming machine is described in DE 35 17 637 A1. However, it is not possible with this forming machine to produce two product parts from a combined part and then discharge them separately whilst carrying out control checks.
In view of the disadvantages of the previously known multi-stage forming machines described above, the invention is based on the following object. There is to be provided a multi-stage forming machine of the type mentioned at the beginning in which product parts produced from a combined part can be discharged from the final forming station quickly, separately and whilst carrying out control checks.
This object is achieved by the forming machine according to the present invention design variants emerge from the.
The essence of the invention is that a multi-stage forming machine with a final forming station for dividing combined parts into in each case two product parts has at least two product-part discharge devices, to which there is in each case assigned a transfer device for transferring a product part from the final forming station to the product-part discharge device.
The fact that the forming machine has at least two product-part discharge devices with assigned transfer devices means that, after dividing a combined part in the final forming station, each product part can be discharged separately.
The transfer devices make it possible for the product parts to be discharged from the final forming station quickly and whilst carrying out control checks. Thanks to the transfer devices, the speed of the forming machine is no longer restricted by the falling speed of the product parts. Moreover, the product parts can be discharged in an alignment suitable for the operations which follow and in a time-controlled manner. Discharging in a way corresponding to the production sequence and whilst carrying out control checks also makes identification of the product parts possible, which considerably facilitates accurate quality control, possible readjustment of the forming machine and rejection of defective product parts. For example, if defective product parts occur on account of transitions of bars from which the combined parts are produced, rejection can be restricted to the product parts directly affected. It is no longer necessary for reasons of safety to reject all the possibly defective product parts discharged in a certain period of time.
Thanks to the transfer devices, the product parts can also be produced more accurately with the forming machine, since the product parts do not strike the chute at high speed as they do in the case of the prior-art forming machines mentioned. The avoidance of surface damage, or at least great reduction in surface damage, makes it possible to reduce or even omit entirely the machining allowances on the product parts.